Due to development of technology, a service using an image in a mobile terminal is provided and widely used. For example, a service for acquiring an image using a camera unit provided in a mobile terminal and a service for receiving an image transmitted from another mobile terminal are widely used. Currently, such a service for using an image in a mobile terminal has developed from a simple use of an image to services such as editing and synthesis of images.
A second generation mobile communication system provides an audio dedicated communication service, whereas a third generation mobile communication system provides a communication service using packet data and multimedia data as well as audio dedicated communication, thereby providing a service using an image. The service using an image in a mobile terminal may include an audiovisual communication service for performing communication while viewing another party. The audiovisual communication service is performed by simultaneously transmitting image data input through a camera unit and audio data input through a microphone. The audiovisual communication service provides a visual function of viewing another party in addition to an audio dedicated communication service through transmission of image data including a user's image, i.e., image transmission. However, because the audiovisual communication service provides an image input through a camera unit, a portion of a user's image that the user may be reluctant to expose is provided to another party, or a particular character of a user that the user desires to portray may be not shown by simply transmitting an image. In order to solve the problem, a replacement image can be provided, or image editing such as image synthesis can be used. However, because the audiovisual communication service transmits an image input through a camera sensor in real time, when an image is edited or when images are synthesized, changes of an object in real time are not reflected in the transmitted images. Therefore, a method of solving the problem is requested.